Special report on diseases of the horse / by Drs. Pearson [and others].

Date:
1903
Catalogue details

Licence: In copyright

Credit: Special report on diseases of the horse / by Drs. Pearson [and others]. Source: Wellcome Collection.

    529/690 (page 451)
    in and beneath the scurf skin, where it hides and lays its eggs and where its young are hatched. It is therefore often difficult to find the parasite on the surface, unless the skin has been heated by a tempo- rary exposure to the sun or in a warm room. Even then it may be needful to tie the scab on the human arm till a pricking is felt, when the acarus will be found in the center of a minute papule caused by its bite. Like other acari, this is wonderfully prolific, a new genera- tion of fifteen individuals being possible every fifteen days, so that in three months the offspring of a single pair ma}- produce generations aggregating 1,500,000 young. The Sarcoptes have less vitality than the nonburrowing acari, as they die in an hour when kept apart from the skin in dry air at a heat of 145° F. They live twelve to fourteen days apart from the skin in the damp air of a stable. On a piece of damp hide they lived till the twenty-fourth day, when they began to die, and all were dead on the twenty-eighth. Symptoms.— The symptoms are an incessant, intolerable, and increas- ing itching of some part of the skin (head, mane, tail, back, etc.), the horse inclining himself toward the hand that scratches him, and mov- ing his lips as if himself scratching. The hairs may be broken and rubbed off, but the part is never entirely bald as in ringworm, and there may be papules or any kind of eruption or open sores from the energy of the scratching. Scabs of any thickness may form, but the special features are the intense itching and the discovery of the acarus. Treatment consists in the removal of the scabs by soapsuds, and, if necessary, a brush and the thorough application of tobacco 1J ounces and water 2 pints, prepared by boiling. This may be applied more than once, and should always be repeated after fifteen days, to destroy the new brood that may have been hatched in the interval. All har- ness and stable utensils should be similarly treated; blankets and rubbers may be boiled, and the stalls should be covered with a white- wash of quicklime, containing one-fourth pound of chloride of lime to the gallon. Parasite: Sarcoptes mutans. Malady: SarCoptic acariasis of fowls.—This parasite belongs to chickens, but can live on the skin of the fox and horse as well. A troublesome mange may therefore at times be traceable to the proximity of a chicken roost. The general symptoms and treatment are essentially the same as for Sarcoptes scal>iei equi. Parasite: Psoroptes equi (Dermatocoptes equi, Dermatodectes equi). Malady: Psoroptic acariasis.—This produces the most frequent mange in horses, and as the parasite only bites the surface and lives among the crusts under the shelter of the hair, it is very easily discovered. It reproduces itself with equal rapidity, and causes similar symptoms to those produced by the Sarcoptes. The same treatment will suffice and is more promptly effectual. The purifying of the stable must be